Initial commit: Developer Tools MVP with visual editor

- Complete React app with 7 developer tools
- JSON Tool with visual structured editor
- Serialize Tool with visual structured editor
- URL, Base64, CSV/JSON, Beautifier, Diff tools
- Responsive navigation with dropdown menu
- Dark/light mode toggle
- Mobile-responsive design with sticky header
- All tools working with copy/paste functionality

node_modules/has-property-descriptors/index.js

@@ -0,0 +1,22 @@
+'use strict';
+
+var $defineProperty = require('es-define-property');
+
+var hasPropertyDescriptors = function hasPropertyDescriptors() {
+	return !!$defineProperty;
+};
+
+hasPropertyDescriptors.hasArrayLengthDefineBug = function hasArrayLengthDefineBug() {
+	// node v0.6 has a bug where array lengths can be Set but not Defined
+	if (!$defineProperty) {
+		return null;
+	}
+	try {
+		return $defineProperty([], 'length', { value: 1 }).length !== 1;
+	} catch (e) {
+		// In Firefox 4-22, defining length on an array throws an exception.
+		return true;
+	}
+};
+
+module.exports = hasPropertyDescriptors;